Problem: On the way to school, Karen became fixated on the puzzle game on her phone!

<image>

The game is played as follows. In each level, you have a grid with n rows and m columns. Each cell originally contains the number 0.

One move consists of choosing one row or column, and adding 1 to all of the cells in that row or column.

To win the level, after all the moves, the number in the cell at the i-th row and j-th column should be equal to gi, j.

Karen is stuck on one level, and wants to know a way to beat this level using the minimum number of moves. Please, help her with this task!

Input

The first line of input contains two integers, n and m (1 ≤ n, m ≤ 100), the number of rows and the number of columns in the grid, respectively.

The next n lines each contain m integers. In particular, the j-th integer in the i-th of these rows contains gi, j (0 ≤ gi, j ≤ 500).

Output

If there is an error and it is actually not possible to beat the level, output a single integer -1.

Otherwise, on the first line, output a single integer k, the minimum number of moves necessary to beat the level.

The next k lines should each contain one of the following, describing the moves in the order they must be done:

  * row x, (1 ≤ x ≤ n) describing a move of the form "choose the x-th row". 
  * col x, (1 ≤ x ≤ m) describing a move of the form "choose the x-th column". 



If there are multiple optimal solutions, output any one of them.

Examples

Input

3 5
2 2 2 3 2
0 0 0 1 0
1 1 1 2 1


Output

4
row 1
row 1
col 4
row 3


Input

3 3
0 0 0
0 1 0
0 0 0


Output

-1


Input

3 3
1 1 1
1 1 1
1 1 1


Output

3
row 1
row 2
row 3

Note

In the first test case, Karen has a grid with 3 rows and 5 columns. She can perform the following 4 moves to beat the level:

<image>

In the second test case, Karen has a grid with 3 rows and 3 columns. It is clear that it is impossible to beat the level; performing any move will create three 1s on the grid, but it is required to only have one 1 in the center.

In the third test case, Karen has a grid with 3 rows and 3 columns. She can perform the following 3 moves to beat the level:

<image>

Note that this is not the only solution; another solution, among others, is col 1, col 2, col 3.

Solution (in JAVA):

Solution:
import java.util.*;

import javax.activation.UnsupportedDataTypeException;

import java.awt.Checkbox;
import java.io.*;

public class KarenGame 
{
	static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;
 
        public FastReader()
        {
            br = new BufferedReader(new
                     InputStreamReader(System.in));
        }
 
        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt()
        {
            return Integer.parseInt(next());
        }
 
        long nextLong()
        {
            return Long.parseLong(next());
        }
 
        double nextDouble()
        {
            return Double.parseDouble(next());
        }
 
        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
	
	static int numberRows, numberCols;
	static int[][] matrix;
	static int[][] original;
	static int[] finalCol = new int[200];
	static int[] finalRow = new int[200];
	static int finalAnswer = Integer.MAX_VALUE;
	static int[] rowArray = new int[200];
	static int[] colArray = new int[200];
	
	public static void main(String[] args) 
	{
		int i, j;
		FastReader reader = new FastReader();
		PrintWriter writer = new PrintWriter (System.out);
		
		numberRows = reader.nextInt();
		numberCols = reader.nextInt();
		
		matrix = new int[numberRows+1][numberCols+1];
		original = new int[numberRows+1][numberCols+1];
		
		for (i=1; i<=numberRows; i++)
		{
			for (j=1; j<=numberCols; j++)
			{
				matrix[i][j] = reader.nextInt();
				original[i][j] = matrix[i][j];
			}
		}
		
		//int answer = Integer.MAX_VALUE;
		int low = Integer.MAX_VALUE;
		
		for (i=1; i<=numberCols; i++)
		{
			low = Math.min (low, matrix[1][i]);
			//System.out.println (matrix[0][i]);
		}

		for (i=0; i<=low; i++)
		{
			update (i);
			//display();
			//System.out.println();
			regenerate();
		}
		
		if (finalAnswer != Integer.MAX_VALUE)
		{
			writer.println (finalAnswer);
			for (i=1; i<=numberRows; i++)
			{
				for (j=1; j<=finalRow[i]; j++)
					writer.println ("row " + i);
			}
			
			for (i=1; i<=numberCols; i++)
			{
				for (j=1; j<=finalCol[i]; j++)
					writer.println ("col " + i);
			}
		}
		else
			writer.println ("-1");
		writer.close();
	}
	
	static boolean check()
	{
		boolean answer = true;
		
		for (int i=1; i<=numberRows; i++)
		{
			for (int j=0; j<=numberCols; j++)
			{
				if (matrix[i][j] != 0)
					answer = false;
			}
		}
		
		for (int i=1; i<=numberCols; i++)
		{
			if (colArray[i] < 0)
				answer = false;
		}
		
		for (int i=1; i<=numberRows; i++)
		{
			if (rowArray[i] < 0)
				answer = false;
		}
		
		return answer;
	}
	
	static void regenerate ()
	{
		for (int i=1; i<=numberRows; i++)
		{
			for (int j=1; j<=numberCols; j++)
				matrix[i][j] = original[i][j];
		}
	}
	
	static void update (int delta)
	{
		int i, j;
		int count=0;
		rowArray = new int[numberRows+1];
		colArray = new int[numberCols+1];
		
		for (i=1; i<=numberCols; i++)
		{
			colArray[i] = matrix[1][i] - delta;
			count += colArray[i];
		}
			
		for (i=1; i<=numberRows; i++)
		{
			rowArray[i] = matrix[i][1] - colArray[1];
			count += rowArray[i];
		}
		
		for (i=1; i<=numberRows; i++)
		{
			for (j=1; j<=numberCols; j++)
				matrix[i][j] -= (colArray[j] + rowArray[i]);
		}
		
		if (check())
		{
			if (count < finalAnswer)
			{
				finalCol = colArray;
				finalRow = rowArray;
				finalAnswer = count;
			}
		}
	}
	
	static void display()
	{
		for (int i=1; i<=numberRows; i++)
		{
			for (int j=1; j<=numberCols; j++)
				System.out.print (matrix[i][j] + " ");
			
			System.out.println ();
		}
		
		for (int i=1; i<=numberRows; i++)
			System.out.print (finalRow[i] + " ");
		
		System.out.println();
		
		for (int i=1; i<=numberCols; i++)
			System.out.print (finalCol[i] + " ");
	
		System.out.println();
	}

}